Toporikova Natalia, Tsao Tzu-Hsin, Wright Terrence Michael, Butera Robert J
Laboratory for Neuroengineering, Georgia Institute of Technology, Mailstop 0250, Atlanta, GA 30332-0250, USA.
J Comput Neurosci. 2011 Nov;31(3):701-11. doi: 10.1007/s10827-011-0340-1. Epub 2011 May 17.
Using two-cell and 50-cell networks of square-wave bursters, we studied how excitatory coupling of individual neurons affects the bursting output of the network. Our results show that the effects of synaptic excitation vs. electrical coupling are distinct. Increasing excitatory synaptic coupling generally increases burst duration. Electrical coupling also increases burst duration for low to moderate values, but at sufficiently strong values promotes a switch to highly synchronous bursts where further increases in electrical or synaptic coupling have a minimal effect on burst duration. These effects are largely mediated by spike synchrony, which is determined by the stability of the in-phase spiking solution during the burst. Even when both coupling mechanisms are strong, one form (in-phase or anti-phase) of spike synchrony will determine the burst dynamics, resulting in a sharp boundary in the space of the coupling parameters. This boundary exists in both two cell and network simulations. We use these results to interpret the effects of gap-junction blockers on the neuronal circuitry that underlies respiration.
我们使用由方波发放神经元组成的双细胞和50细胞网络，研究了单个神经元的兴奋性耦合如何影响网络的发放输出。我们的结果表明，突触兴奋与电耦合的作用是不同的。增加兴奋性突触耦合通常会增加爆发持续时间。对于低至中等强度的值，电耦合也会增加爆发持续时间，但在足够强的值时，会促使转变为高度同步的爆发，此时进一步增加电耦合或突触耦合对爆发持续时间的影响最小。这些效应很大程度上由尖峰同步介导，尖峰同步由爆发期间同相尖峰解的稳定性决定。即使两种耦合机制都很强，一种形式（同相或反相）的尖峰同步也将决定爆发动力学，从而在耦合参数空间中产生一个清晰的边界。这个边界在双细胞和网络模拟中都存在。我们利用这些结果来解释缝隙连接阻滞剂对呼吸基础神经元回路的影响。
